$ sudo apt-get remove db4otool 

Uninstall db4otool including dependent package

If you would like to remove db4otool and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove db4otool 

Use Purging db4otool

If you use with purge options to db4otool package all the configuration and dependent packages will be removed.

$ sudo apt-get purge db4otool 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove db4otool 

See Also,